This change “cifs: release auth_key.response for reconnect.” (commit f5c4ba8) in Linux kernel is authored by Shu Wang <shuwang [at] redhat.com> on Fri Sep 8 18:48:33 2017 +0800.
Description of “cifs: release auth_key.response for reconnect.”
The change “cifs: release auth_key.response for reconnect.” introduces changes as follows.
cifs: release auth_key.response for reconnect.
There is a race that cause cifs reconnect in cifs_mount,
- cifs_mount
- cifs_get_tcp_session
- [ start thread cifs_demultiplex_thread
- cifs_read_from_socket: -ECONNABORTED
- DELAY_WORK smb2_reconnect_server ]
- cifs_setup_session
- [ smb2_reconnect_server ]
auth_key.response was allocated in cifs_setup_session, and
will release when the session destoried. So when session re-
connect, auth_key.response should be check and released.
Tested with my system:
CIFS VFS: Free previous auth_key.response = ffff8800320bbf80
A simple auth_key.response allocation call trace:
- cifs_setup_session
- SMB2_sess_setup
- SMB2_sess_auth_rawntlmssp_authenticate
- build_ntlmssp_auth_blob
- setup_ntlmv2_rsp
Signed-off-by: Shu Wang <shuwang@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>Linux kernel code changes from “cifs: release auth_key.response for reconnect.”
There are 8 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.
fs/cifs/connect.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8d38b22afb2b..0bfc2280436d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -4154,6 +4154,14 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
server->sec_mode, server->capabilities, server->timeAdj);
+ if (ses->auth_key.response) {
+ cifs_dbg(VFS, "Free previous auth_key.response = %p\n",
+ ses->auth_key.response);
+ kfree(ses->auth_key.response);
+ ses->auth_key.response = NULL;
+ ses->auth_key.len = 0;
+ }
+
if (server->ops->sess_setup)
rc = server->ops->sess_setup(xid, ses, nls_info);
The commit for this change in Linux stable tree is f5c4ba8 (patch).